Calculation method and system for short-circuit current of network construction type energy storage access system based on voltage dynamic partitioning

Abstract

The invention discloses a method and a system for calculating short-circuit current of a network construction type energy storage access system based on dynamic voltage partitioning, and belongs to the technical field of power systems. The method comprises the following steps of: giving zero, positive and negative sequence cutoff voltages and positive and negative sequence output current initial values of a division node for a network construction type energy storage access system; the voltage of the division node and the subnet voltage of the first partition are calculated; updating positive and negative sequence output current components according to the sum; converting the updated positive and negative sequence output current components in each subarea of the voltage dynamic subarea into equivalent output current of a subarea subnet; and determining the short-circuit current transmitted to the main power grid by the network construction type energy storage access system. According to the method, the short-circuit current level of the network construction type energy storage access system can be efficiently calculated, the fault can be more accurately identified, and the protection action can be more timely and effectively triggered, so that the safety and the stability of the network construction type energy storage system under the fault working condition are improved.

Description

Technical Field

[0001] This invention relates to the field of power system technology, and more specifically, to a method and system for calculating short-circuit current in a grid-connected energy storage system based on voltage dynamic zoning. Background Technology

[0002] Short-circuit faults are among the most common faults in power system operation, and the resulting short-circuit currents can severely impact the safe and stable operation of the power system. Grid-based energy storage (GFESS), relying on virtual synchronous generator (VSG) control strategies, has become crucial for supporting the stable operation of new power systems. It can actively simulate the inertial response characteristics of synchronous generators, providing dynamic support for high-proportion renewable energy grids and playing a core power source role in off-grid microgrids, black-start applications, and other scenarios. However, current methods for calculating short-circuit currents at fault points after renewable energy / energy storage stations are connected to the system struggle to accurately quantify the impact of changes in control parameters on the short-circuit current. Summary of the Invention

[0003] To address the above problems, this invention proposes a method for calculating the short-circuit current of a grid-connected energy storage system based on dynamic voltage zoning, comprising: For a grid-type energy storage access system, the zero-sequence, positive-sequence, and negative-sequence interruption voltages and initial values ​​of positive-sequence and negative-sequence output currents for the partitioned nodes are given. Based on the zero-sequence, positive-sequence, and negative-sequence interruption voltages and initial values ​​of the positive-sequence and negative-sequence output currents of the partitioned nodes, the current matrix of each partition in the voltage dynamic partition is calculated. Based on the current matrix, the dynamic partition is determined, and the partitioned nodes are then defined. voltage and the Subnet voltage of each zone ; According to the above and Update the positive and negative sequence output current components; The positive and negative sequence output current components updated in each partition of the voltage dynamic partition are converted into the equivalent output current of the partition subnet. Determine whether the error between the current positive and negative sequence interruption voltage and the previous positive and negative sequence interruption voltage meets the accuracy requirements. If it does, determine the positive and negative sequence currents transmitted from the grid-connected energy storage system to the main grid based on the equivalent output current. The short-circuit current of the positive and negative sequence current grid-type energy storage access system.

[0004] Optionally, the formula for calculating the current matrix of each zone in the voltage dynamic partition is as follows: in, and This indicates the nodes after dynamic partitioning. voltage and the first Subnet voltage of each zone; and Represents the partitioning node The equivalent current injected into the power grid; and Indicates after dynamic partitioning, Axis-based node division voltage and the first Admittance matrix of each partition; and Indicates after dynamic partitioning, Axis-based node division voltage and the first Admittance matrix of each partition It is represented as the internal potential of a grid-type energy storage system.

[0005] Optionally, after dynamic partitioning, the nodes are partitioned. voltage and the Subnet voltage of each zone The calculation formula is as follows: in, , , These are represented as the admittance matrix, current matrix, and d-axis sub-nodes of the m-partition, respectively. The admittance matrix.

[0006] Optionally, the formulas for calculating the positive and negative sequence currents transmitted from the grid-connected energy storage system to the main grid are as follows: in, and Representing positive and negative sequence currents respectively Axial components, and The functions represent the voltages of each sub-region after dynamic partitioning. With positive sequence short circuit current Negative sequence short-circuit current The correspondence between them.

[0007] Furthermore, this invention also proposes a short-circuit current calculation system for a grid-type energy storage access system based on dynamic voltage zoning, comprising: The given unit is used to specify the zero, positive, and negative sequence interruption voltages and initial values ​​of positive and negative sequence output currents for the partitioned nodes of the grid-type energy storage access system. The first calculation unit is used to calculate the current matrix of each partition of the voltage dynamic partition based on the zero, positive, and negative sequence interruption voltages and the initial values ​​of the positive and negative sequence output currents of the partitioned nodes. Based on the current matrix, after determining the dynamic partition, the nodes are divided. voltage and the Subnet voltage of each zone ; The second calculation unit is used to calculate according to the... and Update the positive and negative sequence output current components; The third calculation unit is used to convert the updated positive and negative sequence output current components in each partition of the voltage dynamic partition into the equivalent output current of the partition subnet. The output unit is used to determine whether the error between the current positive and negative sequence interruption voltage and the previous positive and negative sequence interruption voltage meets the accuracy requirements. If it does, the positive and negative sequence currents transmitted from the grid-connected energy storage system to the main grid are determined based on the equivalent output current. The short-circuit current of the positive and negative sequence current grid-type energy storage access system.

[0008] Optionally, the formula for calculating the current matrix of each zone in the voltage dynamic partition is as follows: in, and This indicates the nodes after dynamic partitioning. voltage and the first Subnet voltage of each zone; and Represents the partitioning node The equivalent current injected into the power grid; and Indicates after dynamic partitioning, Axis-based node division voltage and the first Admittance matrix of each partition; and Indicates after dynamic partitioning, Axis-based node division voltage and the first Admittance matrix of each partition It is represented as the internal potential of a grid-type energy storage system.

[0009] Optionally, after dynamic partitioning, the nodes are partitioned. voltage and the Subnet voltage of each zone The calculation formula is as follows: in, , , These are represented as the admittance matrix, current matrix, and d-axis sub-nodes of the m-partition, respectively. The admittance matrix.

[0010] Optionally, the formulas for calculating the positive and negative sequence currents transmitted from the grid-connected energy storage system to the main grid are as follows: in, and Representing positive and negative sequence currents respectively Axial components, and The functions represent the voltages of each sub-region after dynamic partitioning. With positive sequence short circuit current Negative sequence short-circuit current The correspondence between them.

[0011] In another aspect, the present invention also provides a computing device, comprising: one or more processors; A processor is used to execute one or more programs; When the one or more programs are executed by the one or more processors, the method described above is implemented.

[0012] In another aspect, the present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed, implements the method described above.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention provides a method for calculating the short-circuit current of a grid-connected energy storage system based on dynamic voltage zoning. The method includes: providing initial values ​​of zero-sequence, positive-sequence, and negative-sequence interruption voltages and positive-sequence and negative-sequence output currents for each node in the grid-connected energy storage system; calculating the current matrix of each zone in the dynamic voltage zoning based on the initial values ​​of the zero-sequence, positive-sequence, and negative-sequence interruption voltages and positive-sequence and negative-sequence output currents for each node; and determining the nodes after dynamic zoning based on the current matrix. voltage and the Subnet voltage of each zone According to the above and The positive and negative sequence output current components are updated; the updated positive and negative sequence output current components in each voltage dynamic partition are converted into the equivalent output current of the partition subnet; it is determined whether the error between the current positive and negative sequence interruption voltage and the previous positive and negative sequence interruption voltage meets the accuracy requirements. If it does, the positive and negative sequence currents transmitted from the grid-connected energy storage system to the main grid are determined based on the equivalent output current; the positive and negative sequence currents are the short-circuit currents of the grid-connected energy storage system. This invention, by dynamically partitioning the system according to different voltage drop levels and combining a practical calculation model for the short-circuit current of grid-connected equipment, can efficiently calculate the short-circuit current level of the grid-connected energy storage system, which helps to more accurately identify faults and trigger protection actions more promptly and effectively, thereby improving the safety and stability of the grid-connected energy storage system under fault conditions. Attached Figure Description

[0014] Figure 1 This is a flowchart of the method of the present invention; Figure 2 This is a flowchart of an embodiment of the method of the present invention; Figure 3 This is a structural diagram of the system of the present invention. Detailed Implementation

[0015] Exemplary embodiments of the invention will now be described with reference to the accompanying drawings. However, the invention may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to fully and completely disclose the invention and to fully convey its scope to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the drawings is not intended to limit the invention. In the drawings, the same units / elements are referred to by the same reference numerals.

[0016] Unless otherwise stated, the terms used herein (including technical terms) have their common meaning as understood by one of ordinary skill in the art. Furthermore, it is understood that terms defined in commonly used dictionaries should be understood to have a meaning consistent with the context of their relevant field, and not to be interpreted as having an idealized or overly formal meaning.

[0017] Example 1: This invention proposes a method S100 for calculating the short-circuit current of a grid-connected energy storage system based on dynamic voltage zoning, as follows: Figure 1 As shown, it includes: S101 provides the zero, positive, and negative sequence interruption voltages and initial values ​​of positive and negative sequence output currents for the partitioned nodes of the grid-type energy storage access system. S102 calculates the current matrix of each partition of the voltage dynamic partition based on the zero, positive, and negative sequence interruption voltages and the initial values ​​of the positive and negative sequence output currents of the partitioned nodes. Based on the current matrix, after determining the dynamic partition, the partitioned nodes are then defined. voltage and the Subnet voltage of each zone ; S103 according to the above and Update the positive and negative sequence output current components; S104 converts the updated positive and negative sequence output current components in each partition of the voltage dynamic partition into the equivalent output current of the partition subnet. S105 determines whether the error between the current positive and negative sequence interruption voltage and the previous positive and negative sequence interruption voltage meets the accuracy requirements. If it does, it determines the positive and negative sequence currents transmitted from the grid-type energy storage access system to the main grid based on the equivalent output current. The short-circuit current of the positive and negative sequence current grid-type energy storage access system.

[0018] The formulas for calculating the current matrix of each voltage dynamic partition are as follows: in, and This indicates the nodes after dynamic partitioning. voltage and the first Subnet voltage of each zone; and Represents the partitioning node The equivalent current injected into the power grid; and Indicates after dynamic partitioning, Axis-based node division voltage and the first Admittance matrix of each partition; and Indicates after dynamic partitioning, Axis-based node division voltage and the first Admittance matrix of each partition It is represented as the internal potential of a grid-type energy storage system.

[0019] Among them, after the fixed-dynamic partitioning, the partitioning nodes are... voltage and the Subnet voltage of each zone The calculation formula is as follows: in, , , These are represented as the admittance matrix, current matrix, and d-axis sub-nodes of the m-partition, respectively. The admittance matrix.

[0020] The formulas for calculating the positive and negative sequence currents transmitted from the grid-connected energy storage system to the main grid are as follows: in, and Representing positive and negative sequence currents respectively Axial components, and The functions represent the voltages of each sub-region after dynamic partitioning. With positive sequence short circuit current Negative sequence short-circuit current The correspondence between them.

[0021] The invention will be further illustrated below with specific examples: In the main power grid, the short-circuit current can be calculated iteratively based on the current injected into the grid by grid-connected energy storage. Specific steps include... Figure 2 As shown, it includes the following: Step 1: Given the zero, positive, and negative sequence interruption voltages for the partitioned nodes and the initial values ​​of positive and negative sequence output currents .

[0022] Step 2: Calculate the current matrix for each partition, and determine the appropriate parameters based on the calculation results. and .

[0023] Step 3: According to and The voltage is updated to reflect the positive and negative sequence of the output current components.

[0024] Step 4: Convert the positive and negative sequence output currents in each grid-type energy storage zone into the equivalent output currents of the zone's subgrid.

[0025] Step 5: Determine if the error between the current positive and negative sequence voltages and the previous positive and negative sequence voltages meets the accuracy requirements. If it does, obtain the positive and negative sequence currents transferred from the grid-connected energy storage to the main grid, i.e., obtain the accurate calculation result of the short-circuit current of the grid-connected energy storage. Otherwise, proceed to step 2. The accurate calculation formula for the short-circuit current of the grid-connected energy storage is: In the formula: and Represents functional relationships; describes the voltage of each sub-region after dynamic partitioning. With positive sequence short circuit current Negative sequence short-circuit current The correspondence between them.

[0026] By combining the above information, the accurate calculation of the current in grid-type energy storage can be completed, and its value can be determined. Under-axis phrase current results and .

[0027] To accurately calculate the short-circuit current of grid-connected energy storage, based on the short-circuit current characteristics analyzed above, a dynamic partitioning approach is adopted to divide the entire power grid, forming a main grid and grid-connected energy storage sub-networks. Nodes connecting the main grid and the grid-connected energy storage sub-networks are designated as split nodes. This is combined with the topological constraints of the power grid and... The admittance matrix of each zone of the power grid is constructed using the following formula: 0,1,2 In the formula, The zero, positive, and negative sequence of the current for grid-type energy storage; This is the node-branch correlation matrix of the power network; For branch admittance.

[0028] Based on the above formula, the current matrix equation for each partition is calculated as follows: In the formula: and This indicates the nodes after dynamic partitioning. voltage and the first Subnet voltage of each zone; and Represents the partitioning node The equivalent current injected into the power grid; and Indicates after dynamic partitioning, Axis-based node division voltage and the first Admittance matrix of each partition; and Indicates after dynamic partitioning, Axis-based node division voltage and the first Admittance matrix of each partition.

[0029] Since the voltage of the dynamically partitioned nodes is the main grid voltage, which is given, the formula can be written as: This section assesses the accuracy of the short-circuit current calculation for grid-type energy storage using the proposed method. The proposed method is compared with existing methods 1, 2, and 3, and the maximum deviation between the calculated and actual results is compared. The formula is as follows: In the formula: and These represent the calculated and actual results of the short-circuit current, respectively.

[0030] Based on the above formula, the deviation results of different methods for calculating short-circuit currents of different magnitudes are analyzed, and the results are shown in Table 1.

[0031] Table 1

[0032] As shown in Table 1, the deviations in short-circuit current calculations using different methods reveal that, for the method of this invention, the F2 values ​​are 0.41%, 0.45%, and 0.46% for short-circuit currents of 25A, 50A, and 75A, respectively, consistently remaining at extremely low levels with minimal fluctuations. In contrast, the F2 values ​​for methods 1, 2, and 3 are significantly higher than those of this invention, and the deviations increase to varying degrees with increasing short-circuit current. This indicates that regardless of the severity of the short-circuit fault (corresponding to different short-circuit current magnitudes), the short-circuit current calculated by the method presented in this paper maintains extremely high accuracy. The protection configuration of grid-based energy storage, such as the setting of protection device action thresholds and the sensitivity verification of fault detection, requires accurate short-circuit current data as a basis. The method of this invention, with its high-precision calculation of short-circuit currents of different magnitudes, provides reliable data support for the protection of grid-based energy storage, helping to more accurately identify faults and trigger protection actions more promptly and effectively. This improves the safety and stability of grid-based energy storage systems under fault conditions, laying a solid foundation for optimizing protection strategies and ensuring reliable operation in practical engineering applications.

[0033] Example 2: Furthermore, this invention also proposes a short-circuit current calculation system 200 for a grid-type energy storage access system based on dynamic voltage zoning, such as... Figure 3 As shown, it includes: Given unit 201, it is used to give the zero, positive and negative sequence interruption voltage and the initial value of positive and negative sequence output current of the partition node for the grid-type energy storage access system; The first calculation unit 202 is used to calculate the current matrix of each partition of the voltage dynamic partition based on the zero, positive, and negative sequence interruption voltages and the initial values ​​of the positive and negative sequence output currents of the partitioned nodes, and to determine the nodes after dynamic partitioning based on the current matrix. voltage and the Subnet voltage of each zone ; The second calculation unit 203 is used to calculate according to the... and Update the positive and negative sequence output current components; The third calculation unit 204 is used to convert the updated positive and negative sequence output current components in each partition of the voltage dynamic partition into the equivalent output current of the partition subnet. Output unit 205 is used to determine whether the error between the current positive and negative sequence interruption voltage and the previous positive and negative sequence interruption voltage meets the accuracy requirements. If it does, it determines the positive and negative sequence current transmitted from the grid-type energy storage access system to the main grid based on the equivalent output current. The short-circuit current of the positive and negative sequence current grid-type energy storage access system.

[0034] The formulas for calculating the current matrix of each voltage dynamic partition are as follows: in, and This indicates the nodes after dynamic partitioning. voltage and the first Subnet voltage of each zone; and Represents the partitioning node The equivalent current injected into the power grid; and Indicates after dynamic partitioning, Axis-based node division voltage and the first Admittance matrix of each partition; and Indicates after dynamic partitioning, Axis-based node division voltage and the first Admittance matrix of each partition It is represented as the internal potential of a grid-type energy storage system.

[0035] Among them, after the fixed-dynamic partitioning, the partitioning nodes are... voltage and the Subnet voltage of each zone The calculation formula is as follows: in, , , These are represented as the admittance matrix, current matrix, and d-axis sub-nodes of the m-partition, respectively. The admittance matrix.

[0036] The formulas for calculating the positive and negative sequence currents transmitted from the grid-connected energy storage system to the main grid are as follows: in, and Representing positive and negative sequence currents respectively Axial components, and The functions represent the voltages of each sub-region after dynamic partitioning. With positive sequence short circuit current Negative sequence short-circuit current The correspondence between them.

[0037] This invention, by dynamically partitioning the access system based on different voltage drop levels and combining it with a practical calculation model for short-circuit current of grid-connected equipment, can efficiently calculate the short-circuit current level of grid-connected energy storage systems. This helps to more accurately identify faults and trigger protection actions more promptly and effectively, thereby improving the safety and stability of grid-connected energy storage systems under fault conditions.

[0038] Example 3: Based on the same inventive concept, this invention also provides a computer device, which includes a processor and a memory. The memory stores a computer program, which includes program instructions. The processor executes the program instructions stored in the computer storage medium. The processor may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing and control core of the terminal, suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions in the computer storage medium to implement corresponding method flows or corresponding functions, thereby implementing the steps of the methods in the above embodiments.

[0039] Example 4: Based on the same inventive concept, this invention also provides a storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device used to store programs and data. It is understood that the computer-readable storage medium here can include both the built-in storage medium in the computer device and extended storage media supported by the computer device. The computer-readable storage medium provides storage space that stores the terminal's operating system. Furthermore, this storage space also stores one or more instructions suitable for loading and execution by a processor. These instructions can be one or more computer programs (including program code). It should be noted that the computer-readable storage medium here can be high-speed RAM or non-volatile memory, such as at least one disk storage device. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the steps of the method in the above embodiments.

[0040] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of the present invention can be implemented using various computer languages, such as the object-oriented programming language Java and the interpreted scripting language JavaScript.

[0041] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0042] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0043] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0044] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0045] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for calculating the short-circuit current of a grid-connected energy storage system based on dynamic voltage zoning, characterized in that, include: For a grid-type energy storage access system, the zero-sequence, positive-sequence, and negative-sequence interruption voltages and initial values ​​of positive-sequence and negative-sequence output currents for the partitioned nodes are given. Based on the zero-sequence, positive-sequence, and negative-sequence interruption voltages and initial values ​​of the positive-sequence and negative-sequence output currents of the partitioned nodes, the current matrix of each partition in the voltage dynamic partition is calculated. Based on the current matrix, the dynamic partition is determined, and the partitioned nodes are then defined. voltage and the Subnet voltage of each zone ; According to the above and Update the positive and negative sequence output current components; The positive and negative sequence output current components updated in each partition of the voltage dynamic partition are converted into the equivalent output current of the partition subnet. Determine whether the error between the current positive and negative sequence interruption voltage and the previous positive and negative sequence interruption voltage meets the accuracy requirements. If it does, determine the positive and negative sequence currents transmitted from the grid-connected energy storage system to the main grid based on the equivalent output current. The short-circuit current of the positive and negative sequence current grid-type energy storage access system.

2. The calculation method according to claim 1, characterized in that, The formula for calculating the current matrix of each zone in the voltage dynamic partition is as follows: in, and This indicates the nodes after dynamic partitioning. voltage and the first Subnet voltage of each zone; and Represents the partitioning node The equivalent current injected into the power grid; and Indicates after dynamic partitioning, Axis-based node division voltage and the first Admittance matrix of each partition; and Indicates after dynamic partitioning, Axis-based node division voltage and the first Admittance matrix of each partition, It is represented as the internal potential of a grid-type energy storage system.

3. The calculation method according to claim 1, characterized in that, After the fixed-dynamic partitioning, the partitioned nodes are... voltage and the Subnet voltage of each zone The calculation formula is as follows: in, , , These are represented as the admittance matrix, current matrix, and d-axis sub-nodes of the m-partition, respectively. The admittance matrix.

4. The calculation method according to claim 1, characterized in that, The formulas for calculating the positive and negative sequence currents transmitted from the grid-connected energy storage system to the main grid are as follows: in, and Representing positive and negative sequence currents respectively Axial components, and The functions represent the voltages of each sub-region after dynamic partitioning. With positive sequence short circuit current Negative sequence short-circuit current The correspondence between them.

5. A system for calculating the short-circuit current of a grid-connected energy storage system based on dynamic voltage zoning, characterized in that, include: The given unit is used to specify the zero, positive, and negative sequence interruption voltages and initial values ​​of positive and negative sequence output currents for the partitioned nodes of the grid-type energy storage access system. The first calculation unit is used to calculate the current matrix of each partition of the voltage dynamic partition based on the zero, positive, and negative sequence interruption voltages and the initial values ​​of the positive and negative sequence output currents of the partitioned nodes. Based on the current matrix, after determining the dynamic partition, the nodes are divided. voltage and the Subnet voltage of each zone ; The second calculation unit is used to calculate according to the... and Update the positive and negative sequence output current components; The third calculation unit is used to convert the updated positive and negative sequence output current components in each partition of the voltage dynamic partition into the equivalent output current of the partition subnet. The output unit is used to determine whether the error between the current positive and negative sequence interruption voltage and the previous positive and negative sequence interruption voltage meets the accuracy requirements. If it does, the positive and negative sequence currents transmitted from the grid-connected energy storage system to the main grid are determined based on the equivalent output current. The short-circuit current of the positive and negative sequence current grid-type energy storage access system.

6. The computing system according to claim 5, characterized in that, The formula for calculating the current matrix of each zone in the voltage dynamic partition is as follows: in, and This indicates the nodes after dynamic partitioning. voltage and the first Subnet voltage of each zone; and Represents the partitioning node The equivalent current injected into the power grid; and Indicates after dynamic partitioning, Axis-based node division voltage and the first Admittance matrix of each partition; and Indicates after dynamic partitioning, Axis-based node division voltage and the first Admittance matrix of each partition, It is represented as the internal potential of a grid-type energy storage system.

7. The computing system according to claim 5, characterized in that, After the fixed-dynamic partitioning, the partitioned nodes are... voltage and the Subnet voltage of each zone The calculation formula is as follows: in, , , These are represented as the admittance matrix, current matrix, and d-axis sub-nodes of the m-partition, respectively. The admittance matrix.

8. The computing system according to claim 5, characterized in that, The formulas for calculating the positive and negative sequence currents transmitted from the grid-connected energy storage system to the main grid are as follows: in, and Representing positive and negative sequence currents respectively Axial components, and The functions represent the voltages of each sub-region after dynamic partitioning. With positive sequence short circuit current Negative sequence short-circuit current The correspondence between them.

9. A computer device, characterized in that, include: One or more processors; A processor is used to execute one or more programs; When the one or more programs are executed by the one or more processors, the method described in any one of claims 1-4 is implemented.

10. A computer-readable storage medium, characterized in that, It contains a computer program, which, when executed, implements the method as described in any one of claims 1-4.

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